Preventing water feed to house from freezing

[Rman]

Ok I know its only july but I had a new well drilled in march 2018 and the feed line from the well head to the house I'm concerned it may freeze this winter. Why because the frost level here is 42 inches deep
The pitless is 48 inches below grade but because the house is over a crawl space the lowest I could drill into
the crawl space is just above the footings at 32 inches. Yes the pipe is now covered after the inspection was done I was not home to stop the workers. Now I wish I would have wrapped the pipe with electric heat tape
Could I use a type of heat blanket for the 5 horizontal feet from the house (well is 10 feet from house) or even bury maybe a foot below grade heat tape in a zig-zag fassion to prevent pipe from freezing??
Our Jan temps go to -15 F. Any suggestions please while the ground is not frozen. Also due to side lot restrictions I cannot get a machine to dig down to the pipe. This was hand dug by two strongback guys
Thanks

 

[Terry]

Have you thought of foam insulation over the piping with dirt over that. Sort of like a blanket interrupting the effect of the cold from above.

 

[Sponsor]

 

[Rman]

Have you thought of foam insulation over the piping with dirt over that. Sort of like a blanket interrupting the effect of the cold from above.

Hi. What type of foam? Spray foam or polisosanurate sheets cut to a foot wide? What r value or multiple sheets. Should I still add a electric heat wrap for backup when temps are extreme
Thanks

 

[Dana]

N

Hi. What type of foam? Spray foam or polisosanurate sheets cut to a foot wide? What r value or multiple sheets. Should I still add a electric heat wrap for backup when temps are extreme
Thanks

None of the above. Polyiso will become saturated when buried, losing most of it's thermal benefit. EPS (the white foam board with macroscopic beads) is fine, as it XPS (blue, pink, green, etc.) EPS is substantially more environmentally friendly than XPS due to the HFC blowing agents used for XPS. (As the HFCs diffuse out over time the performace of XPS drops to that of EPS anyway.)

If you're only going to dig a foot below grade use 2" foam 4' wide centered over your pipe, since the insulation will still be 20" above the pipe. If you dig 2' deep you can drop that to 2' wide and still get at least some reasonable frost protection. The dirt has some R-value, between R1.5-R3 per foot, 2" foam board about R8. The path through the dirt around the foam board from the pipe to the surface needs to be a bit longer than your standard frost depth. A foot wide strip near the surface adds very little path difference, but a 4' wide path 20" above the pipe does.